The present invention relates to a lane departure warning system (LDWS), especially to a lane departure warning system that connects with a global positioning system (GPS) for receiving vehicle speed signals so as to achieve the warning effect while vehicles departing the lane.
As a popular transportation tool, cars are equipped with various electronics such as global positioning systems (GPS), lane departure warning systems (LDWS), or event data recorder (EDR) according to users' needs. The global positioning system (GPS) is a mature product in the market. In combination with a GPS receiver that receives information from GPS satellite to calculate users' own position in real time. Together with a preset electronic map and a display screen, users can know their positions, areas, directions and vehicle speed, accurately locate where they are and easily navigate to where they want to go.
A conventional LDWS mainly includes a camera disposed in vehicles and facing forward to track road images in front the vehicle. For example, while on freeways, images of white lines on two sides of vehicle lanes are captured and input into an electronic control unit (ECU) of LDWS. The ECU consists of a digital signal processor (DSP) and a memory unit such as random access memory (RAM) for dealing with images recognition. The ECU further connects with turn signal lights or speedometers in vehicles so as to obtain vehicle signals for checking whether the dangerous driving occurs. For example, when a car runs at the speed of 60 Km/hr on a highway and the driver haven't turn on turn signal lights (for the lane change), the LDWS gives an alarm by sending signals to initiate a warning unit such as an audible warning unit and/or visual warning unit so as to alert (warn) the driver once the driver departs his lane without signaling.
Until now the ECU of the conventional LDWS still connects to the steering wheel, turn signal lights or speedometers so as to get vehicle (body) signals such as turn signals or vehicle speed. Together with images of the white line between the lanes, the LDWS detects whether is moving out of the lane and gives (or not give) a warning. However, the installation of LDWS affects circuits and equipments in vehicles and causes changes of the equipments or interior design of vehicles. There are various brands and models of cars. Moreover, each car is fitted with different equipments. Thus the installation of LDWS is more troublesome and difficult. People are not willing to change the equipments of interior design of the vehicle for installation of electronic devices so that the willingness to set the LDWS is lowered. This reduces the prevalence of the LDWS. Furthermore, the space inside the vehicle is limited. Yet most of cars are equipped with GPS. The GPS and the LDWS need to be installed respectively and this is inconvenient for users. Moreover, the GPS and the LDWS are independent from each other and unable to be integrated so that the cost of equipments and installation is increased.